Application of high-resolution satellite imagery to transportation: accessibility index extraction approach

This study focuses on transportation application using remotely sensed imagery, in GIS-based environment; GIS is regarded as one of the important and effective methodologies in the transportation problem solving. Generally, transportation application is the complicated task, containing GIS-T (GIS for Transportation) database building and specialized analytical processes; therefore, this study aims at accessibility index extraction using high-resolution imagery, applicable to transportation planning considering an urban environment among transportation. Accessibility, defined as measuring the easiness of reaching from one place to other place, is an element in analyzing the efficiency of a transportation system in its planning process. As for attractive factors in transportation accessibility, many variables such as travel cost, travel time, job opportunity, and the number of facilities or population can be applied. Among them, some parts are associated with visually recognizable features revealed on remotely sensed imagery, and accessibility indices can be utilized to road network or by-pass design problem, and public transit planning. In this study, the gravity-typed accessibility measures are implemented in ArcView-GIS environment with Image Analysis extension. Some ortho-rectified KOMPSAT imageries and IKONOS imageries in local area nearby Seoul-city are used in this study, with digital GIS road layers of the National Geographic Institute in Korea. Conclusively, it is thought that thematic information extraction from high-resolution imagery with GIS databases contributes to expand application fields in remote sensing.